Celebrities rarely shy away from public peddling of dubious ideas about health and science, and 2012 was no exception.

In its annual list of the year's worst abuses against science, the Sense About Science (SAS) campaign also named former US presidential candidate Mitt Romney for spreading misinformation about windows on planes, and Olympic swimmer Michael Phelps for false justifications for peeing in the pool.

To help set the record straight, SAS, a charity dedicated to helping people make sense of science and evidence, invited qualified scientists to respond to some of the wilder pseudo-scientific claims put about by the rich and famous.

It suggested Romney, who wondered aloud in September why aircraft crews don't just open the windows when there's a fire on board, should listen to aeronautical engineer Jakob Whitfield:

"Unfortunately, Mitt, opening a window at height wouldn't do much good," the scientist said. "In fact, if you could open a window whilst in flight, the air would rush out...because air moves from the high pressure cabin to the lower pressure outside, probably causing further injury and damage."

January Jones's dried placenta pills, which the actress admitted in March she consumed after giving birth, win no favour with Catherine Collins, principal dietician at St George's Hospital in London.

"Nutritionally, there's nothing to be gained from eating your placenta - raw, cooked, or dried," Collins said. "Apart from iron, which can be easily found in other dietary choices or supplements, your placenta will provide toxins and other unsavoury substances it had successfully prevented from reaching your baby in utero."

Gary Moss, a pharmaceutical scientist, patiently points out to Palmer that while caffeine may have an effect on cellulite, rubbing coffee granules into the skin is unlikely to work, since the caffeine can't escape the granules to penetrate the skin.

Phelps's claim that it's fine to pee in the pool because "chlorine kills it" is put straight by biochemist Stuart Jones, who reminds him that "urine is essentially sterile so there isn't actually anything to kill in the first place".

And for Cowell, Kay Mitchell a scientist at the Centre for Altitude Space and Extreme Environment Medicine warns that very high levels of oxygen can in fact be toxic - particularly in the lungs, where oxygen levels are highest.

"Celebrity comments travel far and fast, so it's important that they talk sense," said Sense About Science's managing director Tracey Brown. "The implausible and frankly dangerous claims about how to avoid cancer, improve skin or lose weight are becoming ever more ridiculous. And unfortunately they have a much higher profile than the research and evidence."

To encourage more vigilance among celebrity pseudo-scientists in the future, SAS provided a checklist of "misleading science claims" it suggests should be avoided:

"Immune boosting" - you can't and you don't need to

"Detox" - your liver does this

"Superfood" - there is no such thing, just foods that are high in some nutrients

"Oxygenating" - your lungs do this

"Cleansing" - you shouldn't be trying to cleanse anything other than your skin or hair.